lp.cups: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/lp.cups - from package: cups

You may install the required package with command yum install {package}

Error in other languages:
lp.cups: bevel nie gevind nie
lp.cups: comandă negăsită
lp.cups: comando não encontrado
lp.cups: commande introuvable
lp.cups: command not found
lp.cups: käsku ei ole
lp.cups: không tìm thấy lệnh
lp.cups: komanda nerasta
lp.cups: Kommando nicht gefunden.
lp.cups: kommandot finns inte
lp.cups: komut yok
lp.cups: nie znaleziono polecenia
lp.cups: níor aimsíodh an t-ordú
lp.cups: no se encontró la orden
lp.cups: no s'ha trobat l'ordre
lp.cups: opdracht niet gevonden
lp.cups: parancs nem található
lp.cups: perintah tidak ditemukan
lp.cups: príkaz nenájdený
lp.cups: příkaz nenalezen
lp.cups: команда не найдена
lp.cups: командата не е открита
lp.cups: 命令找不到
lp.cups: コマンドが見つかりません